The U.S. Department of State has issued warnings against traveling to Lebanon and Turkey because of the possibility of attacks against U.S. citizens.

The Friday warnings come after a State Department order for a drawdown of non-emergency government personnel and their families in Beirut, Lebanon, and Adana, Turkey.

So far this summer, the State Department has issued several warnings for travel throughout the Middle East, including to Iraq, Pakistan, Yemen, Saudi Arabia, Israel, the West Bank and Gaza.

The warning for Lebanon says "all travel" should be avoided because the potential for a "spontaneous upsurge in violence remains." The warning for Turkey says U.S. citizens should avoid the southeastern part of the country. It does not specifically mention Istanbul, a popular destination in northwest Turkey.

John Rendeiro, vice president of global security and intelligence for International SOS, which provides assistance to travelers abroad, says the State Department seems to be making preparations for possible U.S.-led military intervention in Syria.

"This is sort of preparing in the event that there is a military strike and some kind of action in Syria that will lead to retaliation by Syria and its allies," he says. "If they are taking measures warning their own employees about the threat, they have to notify the public about that."

The State Department portrayed the situation in Lebanon, which shares a border with Syria, as especially dangerous for U.S. citizens.

Lebanese government authorities, the State Department warning says, can't guarantee the protection of visitors if violence should break out.

"Access to borders, airports, roads and seaports can be interrupted with little or no warning," the warning says. "Public demonstrations occur frequently with little warning and have the potential to become violent. Family, neighborhood or sectarian disputes often escalate quickly and can lead to gunfire or other violence with little or no warning. The ability of U.S. government personnel to reach travelers or provide emergency services may be severely limited."

The State Department says that a number of extremist groups operate in Lebanon, including Hezbollah, which the U.S. government has designated a terrorist organization.

Hezbollah and other paramilitary groups have been known to detain foreigners for "political motivations as well as for interrogation - sometimes for hours or longer," the warning says. Kidnapping is also a problem.

Travelers should particularly stay away from the border regions between Lebanon and Syria because the conflict in Syria has led to incidents there that have resulted in deaths in some cases, the warning says.

Lebanon's conflicts with Israel can also pose a problem for travelers.

"Rocket attacks from southern Lebanon into Israel have occurred in the past and remain a potential threat," the warning says. "These attacks frequently provoke a military response from Israel. The rocket attacks and responses occur with no warning."

As for Turkey, the State Department says that there have been no direct attacks on U.S. citizens but that travelers should still avoid demonstrations and large gatherings because they can escalate into violence.

The State Department says anyone who has to travel to the two countries should enroll in the Smart Traveler Enrollment Program to receive updates and make it easier for the U.S. Embassy to stay in touch.

U.S. citizens traveling to Lebanon, in particular, should "keep a low profile, assess their personal security and vary times and routes for all required travel," the warning says.